Home
Class 11
BIOLOGY
Read the following statements about nois...

Read the following statements about noise pollution
I. Sound is measured in units called decibels
II. Human ear is sensitive to sounds ranging from O-180 dB
III. 120 dB is considered as threshold limit of hearing
IV. Noise produced by jet planes while take off is `gt` 150 dB
Which of the above are correct ?

A

All

B

I, II, IV

C

I, II, III

D

II,III, IV

Text Solution

AI Generated Solution

The correct Answer is:
To determine which statements about noise pollution are correct, we will analyze each statement one by one. 1. **Statement I: Sound is measured in units called decibels.** - This statement is correct. Sound intensity is indeed measured in decibels (dB), which is a logarithmic unit used to express the ratio of a particular sound pressure level to a reference level. 2. **Statement II: Human ear is sensitive to sounds ranging from 0-180 dB.** - This statement is partially correct. The human ear can detect sounds from 0 dB (the threshold of hearing) up to about 120-130 dB before experiencing pain or damage. While it is true that the ear can technically perceive sounds up to 180 dB, such levels can cause immediate harm and are not within the normal range of hearing. Therefore, this statement is misleading. 3. **Statement III: 120 dB is considered as threshold limit of hearing.** - This statement is incorrect. The threshold limit of hearing is around 0 dB, while 120 dB is considered the threshold of pain or the level at which sound can cause damage to hearing. The normal threshold of hearing is not 120 dB. 4. **Statement IV: Noise produced by jet planes while take off is greater than 150 dB.** - This statement is correct. The noise produced by jet planes during takeoff can exceed 150 dB, which is indeed very loud and can cause significant hearing damage. **Conclusion:** Based on the analysis: - Statement I is correct. - Statement II is misleading. - Statement III is incorrect. - Statement IV is correct. Thus, the correct statements are I and IV. **Final Answer: Statements I and IV are correct.** ---
Promotional Banner

Similar Questions

Explore conceptually related problems

Consider the following statements about water pollutants. (I) Disease causing pollutants are called pathogens (II) They are bacteria and other organisms that enter water from domestic sewage and animal excreta. (III) Gastrointestinal diseases are caused by Streptococcus faecalis and Escherichia coli bacteria present in human excreta. Correct option(s) is // are.

Consider the following statements about harmful effects of radioactive pollution I.Radiations from nuclear wastes causes mutation at a very high rate II.At high doses nuclear radiations are lethal III.at low doses radiation cause disorders and cancer Which of the statements given above are correct?

Read the following statements about human reproduction : I. A tertiary follicle is characterized by the presence of a fluid - filled cavity called the antrum . II. The labia minora are fleshy folds of tissue , extend down the mons pubis , and surround the vaginal orifice . III. Most of the major organ systems of the fetus formed by the end of the second month of pregnancy . IV. The mammary glands of the female start producing milk during pregnancy. How many statements are incorrect from from the above

Consider the following statements about pollution I.Pollution is an undesirable change in physical ,chemical or biological characteristics of air ,land ,water or soil II.the air act was amended in 1987 to include noise as air pollutant III.In order to control environmental pollution the government of India has passed the environment protection Act ,1976 to protect and improve the quality of our environment Which of the statements given above are correct?

Consider the following statements I. Decrease in hearing sensitivity. II. Increase in hearing sensitivity. III. Change in heart rate and constriction of blood vessels. IV. Change in heart rate but not the constriction of blood vessels. Which of these are correct regarding the effects of noise pollution?

Read the following statements about respiratory system of humans : I. Type II alveoli help in secretion of a chemical surfactant called lecithin , which decreases the surface tension around alveoli. II. The diffusion membrane for exchange of gases is made up of three major cellular layers. III. Binding of oxygen with hemoglobin is primarily related to the partial pressure of O_2 . IV. Every 100 ml of oxygenated blood can deliver around 5 ml CO_2 to the tissues under normal physiological conditions. How many statement is /are correct from the above ?

Consider the following statements about intermolecular and intramolecular hydrogen bonds .ltbr gt I. Both types of H-bonds are temperature dependent. II. Intramolecular H- bonds disapperears on increaassing the concentration III. Intrmolecular H-bonds disppears on decreasing the concentration IV. The boiling point of compounds having intramolecular H-bond are lower than that of those campounds which have intermolecular H- bonds Which of the statement given above are correct ?